• Journal of KIISE:Computer Systems and Theory
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• v.32 no.10
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• pp.512-519
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• 2005

E-BLP security model considers the reliability of the processes that are real subjects in systems. This paper deals with the implementation of the E-BLP model for secure embedded systems. Implemented EBSM(E-BLP Based Security Module) consists of three components: identification and authentication, access control and BRC(Dynamic Reliability Check) that checks the process behavior dynamically. Access Control of EBSM ensures unreliable processes not to access the sensitive objects and the DRC detects the buffer overflow attack by normal user. Besides, the performance overhead of the embedded system applying the EBSM is introduced.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1996.11a
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• pp.336-345
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• 1996

정보 보안의 세 가지 목적은 기밀성, 무결성, 유용성이다. 모든 정보 시스템에서 정보 보안에 관한 필요성이 대두되면서 기밀성뿐만 아니라 무결성도 보장하는 보안 모델이 필요하다. BLP와 Biba는 각각 기밀성과 무결성을 보장하는 보안 모델로서 BLP 모델이 무결성을 고려하지 않기 때문에, Biba 모델은 기밀성을 고려하지 않기 때문에 접근할 수 있는 정보에 한계가 있다. 본 논문에서는 여러 정보시스템 중에서 주로 군사 정보 시스템으로 구현된 BLP와 Biba 모델을 이용해서 기밀성과 무결성을 만족하는 보안 모델을 제시한다. BLP 모델과 Biba 모델을 결합함으로써 BLP 모델을 통해 기밀성을, Biba 모델을 통해 무결성을 보장한다

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1435-1442
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• 2006

The ideal method of safety evaluation is to verify results of execution against all possible operations within operating system, but it is impossible. However, the formal method can theoretically prove the safety on actual logic of operating system. Therefore we explain the contents of the art of the safety verification of security kernel, and make a comparative study of various standardized formal verification tools. And then we assigned PVS(Prototype Verification system) of SRI(Stanford Research Institute) to verify the safety of a modified BLP(Bell & LaPadula) model, the core access control model of multi-lavel based security kernel. Finally, we describe formal specification of the revised BLP model using the PVS, and evaluate the safety of the model by inspecting the specification of the PVS.

• The KIPS Transactions:PartA
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• v.8A no.4
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• pp.391-398
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• 2001

To design and develop secure operating systems, the BLP (Bell-La Padula) model that represents the MLP (Multi-Level Policy) has been widely adopted. However, user\`s security level in the most developed systems based on the BLP model is inherited to a process that is actual subject on behalf of the user, regardless whatever the process behavior is. So, there could be information disclosure threat or modification threat by malicious or unreliable processes even though the user is authorized in the system. These problems can be solved by defining the subject as (user, process) ordered pair and by defining the process reliability. Moreover, when the leveled programs which exist as objects in a disk are executed by a process and have different level from the process level, the security level decision problem occurs. This paper presents an extended BLP (E-BLP) model in which process reliability is considered and solves the security level decision problem. And this model is implemented into the Linux kernel 2.4.7.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.802-804
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• 2001

안전한 운영체제를 개발하기 위한 제안된 모델중 대표적인 BLP(Bell&LaPadula)모델은 주체(사용자)의 보안등급이 접근주체인 프로세스에 그대로 상속됨으로서 악의적인 프로세스에 의한 정보의 흐름, 변조, 누출 등의 위협을 고려하지 않는 단점을 지니고 있다. 본 논문에서는 프로세스를 신뢰영역과 비 신뢰영역으로 구분하고 악의적인 행위를 유발할 수 있는 프로세스들의 접근을 강력히 통제하는 프로세스 기반의 확장된 BLP 모델을 제안하고 시스템에 적용을 위한 아키텍쳐를 설계한다.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2002.05a
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• pp.79-84
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• 2002

The bottom-leaded plastic(BLP) packages have attracted substantial attention since its appearance in the electronic industry. Since the solder materials have relatively low creep resistance and are susceptible to low cycle fatigue, the life of the solder joints under the thermal loading is a critical issue for the reliability The represent study established a finite element model for the analysis of the solder joint reliability under thermal cyclic loading. An elasto-plastic constitutive relation was adopted for solder materials in the modeling and analysis. A 28-pin BLP assembly is modeled to investigate the effects of various epoxy molding compound, leadframe materials on solder joint reliability. The fatigue life of solder joint is estimated by the modified Coffin-Hanson equation. The two coefficients in the equation are also determined. A new design for lead is also evaluated by using finite element analysis. Parametric studies have been conducted to investigate the dependence of solder joint fatigue life on various package materials.

• Convergence Security Journal
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• v.2 no.2
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• pp.49-58
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• 2002

RBAC(Role Based Access Control) is an access control method based on the application concept of role instead of DAC(Discretionary Access Control) or MAC(Mandatory Access Control) based on the abstract basic concept. Model provides more flexibility and applicability on the various computer and network security fields than the limited 1functionality of kernel access control orginated from BLP model. In this paper, we propose $ERBAC_0$ (Extended $RBAC_0$ ) model by considering subject's and object's roles and the role hierarchy result from the roles additionally to $RBAC_0$ base model. The proposed $ERBAC_0$ model assigns hierarchically finer role on the base of subject and object level and provides flexible access control services than traditional $RBAC_0$ model.

• Advances in Computational Design
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• v.6 no.1
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• pp.15-30
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• 2021

With improvement in innovative manufacturing technologies, it became possible to fabricate any complex shaped structural design for practical applications. This allows for the fabrication of curvilinearly stiffened pressure vessels and pipes. Compared to straight stiffeners, curvilinear stiffeners have shown to have better structural performance and weight savings under certain loading conditions. In this paper, an optimization framework for designing curvilinearly stiffened composite pressure vessels and pipes is presented. NURBS are utilized to define curvilinear stiffeners over the surface of the pipe. An integrated tool using Python, Rhinoceros 3D, MSC.PATRAN and MSC.NASTRAN is implemented for performing the optimization. Rhinoceros 3D is used for creating the geometry, which later is exported to MSC.PATRAN for finite element model generation. Finally, MSC.NASTRAN is used for structural analysis. A Bi-Level Programming (BLP) optimization technique, consisting of Particle Swarm Optimization (PSO) and Gradient-Based Optimization (GBO), is used to find optimal locations of stiffeners, geometric dimensions for stiffener cross-sections and layer thickness for the composite skin. A cylindrical pipe stiffened by orthogonal and curvilinear stiffeners under torsional and bending load cases is studied. It is seen that curvilinear stiffeners can lead to a potential 10.8% weight saving in the structure as compared to the case of using straight stiffeners.

• Journal of Life Science
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• v.18 no.9
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• pp.1202-1206
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• 2008

The present investigation demonstrates HLA-DR and PGP9.5 double positive cells accumulate thymus cortical region in normal baboon thymus and baboon lung. But, these cells disappeared in thymus and lung of bronchopulmonary dysplasia (BPD) animals. 125d GC animal model is more suitable for BPD than 140d GC animal. Anti-bombesin antibody, 2A11 treated baboon recover normal level of HLA-DR positive cells from BPD animal. In addition, thymocytes show responsiveness for bombesin. These observation suggest that blocking BLPs protects a chronic lung injury by BPD and 2A11 is possible agent for passive therapy of BPD.